This medication is used to treat certain mental/mood disorders (such as schizophrenia). Thioridazine belongs to a class of drugs known as antipsychotics. It works by helping to restore the balance of certain natural substances in the brain.

This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

This drug may also be used for short periods of time for very severe depression when the patient is also anxious.

Take this medication by mouth with or without food as directed by your doctor, usually 2 to 4 times a day. The dosage is based on your medical condition and response to treatment.

Once your condition improves and you are better for a while, your doctor may work with you to reduce your regular dose. This may be done over time. Do not stop your medication or lower your dose without talking with your doctor first. Some conditions may become worse when the drug is stopped abruptly. Your dose may need to be gradually reduced.

Use this medication regularly in order to get the most benefit from it. To help you remember, use it at the same times each day.

Tell your doctor if your condition lasts or gets worse.

Dizziness, lightheadedness, drowsiness, difficulty urinating, constipation, restlessness, headache, and blurred vision may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Dizziness and lightheadedness can increase the risk of falling. Get up slowly when rising from a sitting or lying position.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• shaking (tremors)
• mask-like facial expression
• shuffling walk
• muscle spasms
• signs of infection (such as sore throat that doesn't go away, fever)
• vision changes (such as vision loss, sudden difficulty seeing at night, brown-tinged vision)

Get medical help right away if you have any very serious side effects, including:

• severe dizziness
• fainting
• slow heartbeat
• seizures

Thioridazine may rarely cause a condition known as tardive dyskinesia. In some cases this condition may be permanent. Tell your doctor right away if you develop any unusual/uncontrolled movements (especially of the face, lips, tongue, arms or legs).

In rare cases, thioridazine may increase your level of a certain chemical made by the body (prolactin). For females, this increase in prolactin may result in unwanted breast milk, missed/stopped periods, or difficulty becoming pregnant. For males, it may result in decreased sexual ability, inability to produce sperm, or enlarged breasts. If you develop any of these symptoms, tell your doctor right away.

This medication may rarely cause a very serious condition called neuroleptic malignant syndrome (NMS). Get medical help right away if you have any of the following symptoms:

• fever
• muscle stiffness/pain/tenderness/weakness
• severe tiredness
• severe confusion
• sweating
• fast/irregular heartbeat
• dark urine
• signs of kidney problems (such as change in the amount of urine)

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking thioridazine, tell your doctor or pharmacist if you are allergic to it; or to other phenothiazines (such as chlorpromazine); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• nervous system problems (such as seizures, drug/alcohol overdose, severe drowsiness)
• blood pressure problems
• certain blood problems (such as low white blood cell count)
• Parkinson's disease
• low enzymes needed to remove drugs from the body (slow hydroxylator)

Thioridazine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.

The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using thioridazine, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions:

• certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG)
• family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death)

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using thioridazine safely.

This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness.

Older adults may be more sensitive to the side effects of this drug, especially dizziness, lightheadedness, drowsiness, confusion, constipation, difficulty urinating, and QT prolongation (see above). Dizziness, lightheadedness, drowsiness, and confusion can increase the risk of falling.

During pregnancy, this medication should be used only when clearly needed. Babies born to mothers who have used this drug during the last 3 months of pregnancy may rarely develop symptoms including muscle stiffness or shakiness, drowsiness, feeding/breathing difficulties, or constant crying. If you notice any of these symptoms in your newborn especially during their first month, tell the doctor right away.

Since untreated mental/mood problems (such as schizophrenia, depression) can be a serious condition, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately discuss with your doctor the benefits and risks of using this medication during pregnancy.

It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include:

• asunaprevir
• cabergoline
• lithium

Many drugs besides thioridazine may affect the heart rhythm (QT prolongation), including amiodarone, dofetilide, pimozide, procainamide, quinidine, sotalol, macrolide antibiotics (such as erythromycin), ziprasidone, among others.

Other medications can affect the removal of thioridazine from your body, which may affect how thioridazine works. Examples include bupropion, cinacalcet, dacomitinib, duloxetine, mirabegron, pindolol, propranolol, rolapitant, terbinafine, certain SSRI antidepressants (such as fluoxetine, fluvoxamine, paroxetine), among others.

Thioridazine can speed up the removal of other drugs from your body, which may affect how they work. Examples of affected drugs include elacestrant, lonafarnib, mavacamten, ombitasvir/paritaprevir/ritonavir, among others.

This medication may decrease the effectiveness of hormonal birth control such as pills, patch, or ring. This could cause pregnancy. Discuss with your doctor or pharmacist if you should use reliable backup birth control methods while using this medication. Also tell your doctor if you have any new spotting or breakthrough bleeding, because these may be signs that your birth control is not working well.

Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests (such as eye exams, potassium levels, EKG) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.